Paper-clamping device for rotary duplicating machines



July 1., 1958 v R R 2,841,393

PAPER-CLAMPING DEVICE FOR ROTARY DUPLICATING MACHINES Filed Sept. 3. 1954 INVENTOR EDGAR RUTISHAUSER BY MM M atent fifice 2,841,393 Patented July 1, 1958 PAPER-CLANIPING DEVICE FOR ROTARY DUPLICATING MACHINES Edgar Rutishauser, Zurich, Switzerland Application September 3, 1954, Serial No. 454,189 Claims priority, application Germany March 19, 1954 7 Claims. (Cl. 271-61) This invention relates to a paper-clamping device for rotary duplicating machines, and more particularly to a mechanism for adjusting the clamping jaws of rotary dnplicators.

With modern duplicators, the stack of blank sheets is held on the paper-supporting table by means of clamping jaws which prevent more than one sheet from being fed to the machine at any one time. There are also provisions for shifting the entire clamping device at right angles to the feeding direction. The clamping device itself and the means for efifecting its lateral movements are usually actuated by control means which protrude beyond the sides of the machine, which sides constitute the cylinder bearings.

The primary object of my present invention is to provide a single actuating or control organ to perform the various manipulations required to adjust the clamping jaws.

, Another object of the invention is to arrange the actuating or control organ within the space occupied by the body of the machine so that the organ will not project beyond such space.

Other objects of my invention will appear from the following description.

In order that the present invention may be fully understood, an illustrative embodiment is described hereinafter in detail, by way of example, and shown in the accompanying drawing in which:

Fig. 1 is a plan view of the paper-supporting table of the device according to the invention, viewed from below;

Fig. 2 illustrates a detail of my device, used for fine adjustments of the lateral position of the device;

Fig. 3 shows a section taken in the plane of the line I-I of Fig. 2;

Fig. 4 shows the control organ or control knob of my device;

Fig. 5 shows the control knob in another position; and

Fig. 6 is a perspective view of the paper-supporting table.

Referring to the drawing in greater detail, to the plate 1 or the main part of the paper-supporting table is pivotally joined the plate In or the end part of the table. In its operating position, the part 1a makes with the part 1 an angle on which is less than 45. Due to this inclination of the end part of the table, a stack of blank sheets resting on the end part becomes stiffened so that it cannot warp under the pressure of the clamping jaws. When the machine is not in use, the plate 1a may be tilted upwardly about an angle of 90 with respect to the plane of the table so that the space required for the storage of the machine will be reduced.

Below the part 1a of the table there is a control knob 3 mounted on a threaded spindle 2. The spindle extends below the main part 1 of the table in the paperfeeding direction. It is provided with right hand and left hand threads which threadedly extend through bushings 2a and 2b, respectively, which bushings are secured to the center members of a lazy tongs 4. The spindle is connected to the control knob 3 by means of disengageable coupling members 19 and 20, the former being a toothed wheel or gear, and the latter being formed by matingly shaped internal teeth. In the embodiment of the invention, selected for illustration, the toothed wheel 19 is fixedly mounted on an end of the spindle 2, and the teeth 20 are provided in the control knob 3 which is axially slidable and rotatable with respect to the spindle. When the knob 3 is turned with the gear 19 meshing with the teeth 20, the lazy tongs are either contracted or extended. The table part 1 has laterally extending slots 22 therein above the lazy tongs 4, and guide sleeves 7 are secured to the ends of the lazy tongs and carry clamping jaws 5 and 6 having portions which project through the slots 22 above the paper-supporting table (see Fig. 6). Thus, by actuating the knob 3, the lazy tongs are either contracted or extended to cause the jaws 5 and 6 to either exert a clamping pressure on a stack of blank sheets, or release such pressure. In order to mount the assembly of the spindle 2, lazy tongs 4, sleeves 7 and clamping jaws 5 and 6 for movement, as a unit, transversely with respect to the table part 1, the guide sleeves 7 are slidably mounted on a guide rod 8 which is supported by the table part 1 and extends below the slots 22 in the transverse direction with respect to the direction or" the paper feed. Further, a bushing 9 slidably receives the spindle 2 and has rods 10 extending laterally from the opposite sides thereof. The rods 10 are slidably received in bearings 11 and 12 which are secured to the underside of the table part or plate 1.

The illustrated device embodying the present invention further has releasable latching means operative to prevent lateral movement, as a unit, of the assembly of the spindle 2, lazy tongs 4, sleeves 7 andclamping jaws 5 and 6. Such releasable latching means includes a laterally extending toothed rack 14 carried by the table part 1, a bow-like double-acting pawl 13 mounted, at its center, on the spindle 2 and engageable, at its opposite ends, with the rack 14 to hold the spindle against lateral displacement relative to the table, and a chordal member 15 extending across the pawl. A tube 21 is axially slidable on the spindle 2 between the knob 3 and the chordal member 15 so that, when the knob 3 is displaced axially along the spindle from the position of Fig. 1 to the position shown in Fig. 4, for disengaging the coupling 19, 20, the extension tube 21 pushes the chordal member 15 forward, and the latter acts on the pawl 13 to disengage the latter from its previous engagement with the laterally extending rack 14. With the pawl 13 in disengaged condition, the spindle 2, together with the lazy tongs 4 and the clamping jaws 5 and 6, may be moved in lateral directions, as indicated by the arrows B and C in Fig. 6. The guide sleeves 7 slide along the rod 8, and the rods 10 slide in the bearings 11 and 12.

A difierent position of the control knob 3 is shown in Fig. 5, wherein the control knob has been pushed still further along spindle 2 so that a spur gear 16, which is mounted on the spindle and connected with the control knob (see also Figs. 1 and 4), is brought into engagement with a rack 17 formed on an offset edge portion 18 of the paper-supporting table (see Fig. 3). By turning knob 3 in the axial position of Fig. 5, it is thus possible to obtain fine adjustments of the lateral position of the spindle 2 and, accordingly, of the entire clamping device.

It is believed that the construction of the form of apparatus for practicing the invention, as shown and described hereinbefore, and the operation thereof, as well as the many advantages offered by the construction of the invention, will be understood from the foregoing detailed description. Some of the features of the invention are reviewed hereinafter.

y pap nc ar p s deri e nr ro up i t i a-i chines includes a control organ; disposed below the table S pp r i th P p to be p h d- T e c tro organ is provided on a threaded spindle which also extends below the table andis operatively connected with so-called lazy tongs. Each endof the lazy tongs carriesa clamping jaw. On turning the control organ which is constituted by a knob, the clamping jaws are caused by the lazy tongs to move towardone another.

My invention further provides that the spindle and, hence, theentire clamping device may be moved in the direction normal to the longitudinal axis of thcspindle with the aid of means controlled 'by the control knob;

According to one fe ture of my invention, the control knob alsoipermits fine adjustments of the threaded spindle in the direction normal to its longitudinal axis.

My. invention provides a single control organ which suffices to close the clamping 'jaws and to ensure both coarse and fine lateral adjustments of the clamping mechanism. It will be apparent that the control organ is arranged within the over-all space occupied by the machine.

It will be clear that while Ihave shown and described my invention in one form only, many changes and modifications may be made without departing from the spirit of the invention defined in the following claims.

. I-clairn:

1. Paper. clamping-'devicesfor rotary duplicating machinescomprising a table. for. supporting a stackof the paper to be printed, a threaded spindle extending longitudinally' below saidtable, two-armed lazy tongs operatively connectedto said spindle and extending laterally at the opposite sides of the latter, said table having later: ally extending slotstherein, clamping jaws connectedto the opposite ends of said lazy tongs and having portions extending through said slots so that said jaws are moved toward and away from eachother, to respectively clamp and release a stack of paper therebetween, by rotation of said spindle means slidably supporting said spindle and lazy tongs for bodily lateral movement has a unit with respect to said table, releasable locking means normally holding said spindle and lazy tongs against bodily lateral movement with respect to said table, a control knob on said spindle, coupling means releasably connecting said knob to said spindle for normally effecting rotation of the 'latter, said knob being movable relative to said spindle to disengage said coupling means and simultaneously to release said locking means for permitting lateral adjustment of said spindle and lazy tongs as a unit, and means operable by said knob upon movement of the latter for release of said coupling means and locking means to effect fine lateral adjustment of the position of said spindle and lazy tongs, whereby said control knob is manipulable to controlthe positions of said jaws with respect'to each other, as well as withrespect to said direction.

2. Paper clampingdevice according to claim 1; wheretable in the lateral in said means supporting the spindle and lazy tongs for lateral movement with respect to the table includes a laterally extending guide rod between said table and said 3. Paper clamping device according to claim 1;wherein said means supporting the and lazy tongs for lateral movement with respectto the tableincludes a bushing on said spindle, rods extending laterally from said bushing in opposed directions, and bearings depending from said table and slidably receiving said laterally extending rods. a

4. Paper clamping device according to claim 1; wherein said knob is axially movablerelative to said spindle for release of said coupling means; and wherein said locking means includes a laterally extending toothed rack carried by said table, a bow-like double-acting pawl on said spindle engageable with said rack, a chordal member slidable on said spindle and extending across said pawl, and an extension tube slidable on said spindle'between said knob and chordal member so that, when said knob is displaced axially to release said coupling means, said extension tube is similarly displaced against said chordal.

spindle and lazy tongs includes a laterally'extending'gear rack on an onset edge of said table, a spur gear on said knob and rotatable with the latter relative tosaid spindle andin mesh'with said gear rack when the knob is axially displaced'to disengage said coupling means and release said locking means, the extent of the axial displacement; of the knob required for bringing said spur gear into meshing engagement with the related gear rack being 7 greater than the axial. displacement necessary for disengagement of said coupling means andrelease of said locking meansso that, upon axial displacement of said knobto an extent just sufl'icienttodisengage said coupling means and release said Iocking means, said knob.

can be shifted laterally to effect coarse'lateral adjustment of thespindle and lazy tongs, while further axial displace- .inent of the knob, to mesh said spur gear with the related gear rack, makes it possible to'achiev'e' fine lateral adjustmetn of the spindle and lazy tongs by rotation of the knob.

6. Paper clamping device according to claim 5; wherein said couplingImeans includes a" gear fixed on said spindle, said knob having a recess in the end thereof facing away from said extension tube and formed with internal teeth adapted'to mesh with the teeth of said gear fixed on the spindle, said bow-like pawl yieldably' urgin g said knob axially in the direction causing said' gear fixed on the spindle to engage in said recess of the knob. i i

7. Paper clamping device according to claim 1; wherein said table includes a main part and an end part located above said control knob and being angularly adjustable with respect to said'main part, said end part making an angle of less than 45 with said-main part during the operation of an associated duplicating machine so that a stack of paper onsaid table is bent in the longitudinal direction to increase the lateral stiffness of the stack and prevent buckling of the latter under the pressure exerted thereon by said clamping jaws, and said end part being arranged at 9 0? to said main part during storage of thepaper clamping device thereby-to decrease. the spacere quired for such storage. f

References Cited in the tile of this patent UNITED STATES PATENTS Peterson Dec..16, 19,41 

